is a traditional aromatic plant used to produce linalool and borneol flavors in southern China; however, its leaves also contain many other unutilized essential oils. Herein, we report geographic ...relationships for the yield and compositional diversity of
essential oils. The essential oils of 974 individual trees from 35 populations in 13 provinces were extracted by hydrodistillation and analyzed qualitatively and quantitatively by gas chromatography-mass spectrometry and gas chromatography-flame ionization detection, respectively. Oil yields ranged from 0.01% to 3.46%, with a significantly positive correlation with latitude and a significantly negative correlation with longitude. In total, 41 compounds were identified, including 15 monoterpenoids, 24 sesquiterpenoids, and two phenylpropanoids. Essential oil compositions varied significantly among individuals and could be categorized into various chemotypes. The six main chemotypes were eucalyptol, nerolidol, camphor, linalool, selina, and mixed types. The other 17 individual plants were chemotypically rare and exhibited high levels of methyl isoeugenol, methyl eugenol, δ-selinene, or borneol. Eucalyptol-type plants had the highest average oil yield of 1.64%, followed in decreasing order by linalool-, camphor-, mixed-, selina-, and nerolidol-type plants. In addition, the five main compounds exhibited a clear geographic gradient. Eucalyptol and linalool showed a significantly positive correlation with latitude, while selina-6-en-4-ol was significantly and negatively correlated with latitude. trans-Nerolidol and selina-6-en-4-ol showed significantly positive correlations with longitude, whereas camphor was significantly and negatively correlated with longitude. Canonical correspondence analysis indicated that environmental factors could strong effect the oil yield and essential oil profile of
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We synthesized a series of quinazolinone derivates as tyrosinase inhibitors and evaluated their inhibition constants. We synthesized 2-(2,6-dimethylhepta-1,5-dien-1-yl)quinazolin-4(3H)-one (Q1) from ...the natural citral. The concentration, which led to 50% activity loss of Q1, was 103 ± 2 μM (IC50 = 103 ± 2 μM). Furthermore, we considered Q1 to be a mixed-type and reversible tyrosinase inhibitor, and determined the KI and KIS inhibition constants to be 117.07 μM and 423.63 μM, respectively. Our fluorescence experiment revealed that Q1 could interact with the substrates of tyrosine and L-DOPA in addition to tyrosinase. Molecular docking studies showed that the binding of Q1 to tyrosinase was driven by hydrogen bonding and hydrophobicity. Briefly, the current study confirmed a new tyrosinase inhibitor, which is expected to be developed into a novel pigmentation drug.
Pyranoquinolinones synthesized from citral were used for Cu-catalyzed N-arylation with a wide range of arylboric acids. The reaction proceeded well with a broad substrate scope, providing a direct ...way to access highly functional pyranoquinolinone core structure derivatives in yields of up to 80%. Compared to citral, the compounds we obtained have a much better inhibitory effect on HeLa cervical cancer cells, and compound 3p has an IC50 value of 4.6 μM, lower than cisplatin’s 5.9 μM.
The removal of fine particles from coal-fired flue gas using chemical and physical reactions was investigated experimentally in a wet flue gas desulfurization (WFGD) system with a cascade of ...double-towers system. The flue gas particles were collected by an Andersen 8-stage impactor, and their mass concentration and particle size distribution were investigated. Based on analysis via scanning electron microscopy/energy dispersive X-ray spectrometry (SEM-EDX), X-ray diffraction (XRD) and inductively coupled plasma atomic emission spectrometry (ICP-AES), the morphological characteristics and the major and minor-element concentrations of particles were studied. The results indicate that the size distribution of fly ash particles at the inlet of the WFGD system was typically distributed bimodally. Although a bimodal distribution was still observed after the desulfurization, all the peaks had decreased. Furthermore, the content of S and Ca increased. Fine particles in the flue gas consisted of about 26.48% limestone and 41.19% gypsum particulate matter, eventually forming the Ca_(11.3)Al_(14)O_(32.3) crystal. The net removal efficiency of the double tower WFGD system reached 84.16% for the original particles, which was similar to that of the conventional single tower system. The entrainment of recirculated slurry contributed to the submicron particle emissions, and the total removal efficiency of the double tower WFGD system decreased to 51.1%.
In the present work, stable organogels and hydrogels could be formed by dimeric-dehydrocholic acid derivative (DDAD) in different solvents. Compared with the organogels, the hydrogels formed by DDAD ...were found to be thermal reversible and had higher gel-to-solution transition temperature. The supramolecular structures in the organogels and hydrogels were further studied by using transmission electron microscopy (TEM) and atomic force microscopy (AFM). TEM and AFM images of the supramolecular gels showed that the solvent effects played a crucial role in morphological structures. Specifically, the organogel had a three-dimensional porous network structure. While, the hydrogel had a supramolecular structure made up of long fibers. Fourier transformation infrared spectroscopy (FT-IR) showed that multiple hydrogen bonds among the gelator molecules were the main driving forces in gel formation. On this base, the solvent effects on the gelation abilities and thermal stability were discussed. Thus, the present study provides a solvent-induced self-assembly approach and contributes substantially to the development of the supramolecular gels as soft materials.
Supramolecular gels have received a lot of attention due to their unique properties and potential applications. However, it is difficult to determine the relationship between the molecular structures ...of gelators and the influencing factors. To understand how the different alkyl chain isomers govern the gelation behaviors, benzene-1,3,5-tricarboxamide (BTA) derivatives have been designed and synthesized. Although these derivatives have the same molecular formula, the alkyl chain configurations are different on the amide bonds. The gelation behaviors indicated that BTA derivatives had obviously different gelation properties. Specifically, BTA–3C8 could only form organogels in cyclohexane, and it exhibited poor gelation properties. BTA–3MeC7 formed stable organogels in low-polar solvents. BTA–3EtC6 possessed excellent gelation properties, and it formed organogels in almost all the tested solvents. BTA–3BuC4 exhibited gelation abilities in a limited number of solvents. The thermal stabilities and the morphologies of organogels were determined. The results indicated that the alkyl chain groups of gelators significantly affected the thermal stabilities and the supramolecular structures of organogels. Using the FT–IR technique and XRD characterization, we investigated the main driving force and the molecular stacking patterns of the gelators. The results indicated that hydrogen bonds acted as the main driving force for the formation of gels. Moreover, the gelator molecules were self-assembled to form ordered and layered structures. Finally, the mechanism of the organogel formation was proposed. This study provides a useful idea for the preparation of soft materials with controllable supramolecular structures or special properties.
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Supramolecular hybrid materials based on polyoxometalates (POMs) have attracted intense attention, due to their wide range of unique properties and potential applications. However, the relationships ...between supramolecular structures and influencing factors are challenging to determine. To provide a deeper understanding, this work discusses how molecular structures and solution components affect the self-assembly process of two barbituric acid–POM hybrids. We have designed and synthesized two barbituric acid–POM hybrids with similar molecular structures. The morphologies of the hybrids in the supramolecular self-assembly were closely investigated under various solvent conditions. The correlation between supramolecular structures and molecular structures and solution components was examined. The barbituric acid–POM hybrids, prepared in methanol/chloroform mixed solution at a volume ratio of 1:3, could be potentially used as effective catalysts for the degradation of organic dyes. This study provides a protocol for preparing supramolecular hybrid materials with controlled supramolecular structures or peculiar properties.
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A polyoxometalate (POM)-cholic acid hybrid was prepared by grafting cholic acid moieties on two sides of the POM cluster. The self-assembly behaviors developed by POM-cholic acid hybrid molecules in ...a methanol/toluene mixed solution were studied to improve the control of molecular architectures. Under the control conditions, nanoparticles and vesicles in solution systems were formed using simple experimental manipulation. The nanoparticles were prepared with hybrid molecules using ultrasonic manipulation, while the vesicles were formed through aging manipulation. More specifically, these different morphologies were thoroughly studied by transmission electron microscopy (TEM), atomic force microscopy (AFM), Fourier-transform infrared (FTIR), and X-ray diffraction (XRD) analyses. The results revealed that the self-assembly behaviors of hybrid molecules can be readily regulated through simple experimental manipulations. Additionally, we also propose the mechanisms of formation of nanoparticles and vesicles. This work may provide a smart approach to the effective design and fabrication of multifunctional supramolecular materials with adjustable structural architectures.
Cinnamomum camphora is a traditional aromatic plant used to produce linalool and borneol flavors in southern China; however, its leaves also contain many other unutilized essential oils. Herein, we ...report geographic relationships for the yield and compositional diversity of C. camphora essential oils. The essential oils of 974 individual trees from 35 populations in 13 provinces were extracted by hydrodistillation and analyzed qualitatively and quantitatively by gas chromatography-mass spectrometry and gas chromatography-flame ionization detection, respectively. Oil yields ranged from 0.01% to 3.46%, with a significantly positive correlation with latitude and a significantly negative correlation with longitude. In total, 41 compounds were identified, including 15 monoterpenoids, 24 sesquiterpenoids, and two phenylpropanoids. Essential oil compositions varied significantly among individuals and could be categorized into various chemotypes. The six main chemotypes were eucalyptol, nerolidol, camphor, linalool, selina, and mixed types. The other 17 individual plants were chemotypically rare and exhibited high levels of methyl isoeugenol, methyl eugenol, δ-selinene, or borneol. Eucalyptol-type plants had the highest average oil yield of 1.64%, followed in decreasing order by linalool-, camphor-, mixed-, selina-, and nerolidol-type plants. In addition, the five main compounds exhibited a clear geographic gradient. Eucalyptol and linalool showed a significantly positive correlation with latitude, while selina-6-en-4-ol was significantly and negatively correlated with latitude. trans-Nerolidol and selina-6-en-4-ol showed significantly positive correlations with longitude, whereas camphor was significantly and negatively correlated with longitude. Canonical correspondence analysis indicated that environmental factors could strong effect the oil yield and essential oil profile of C. camphora.
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